diff --git a/doc/tutorials/introduction/cross_referencing/tutorial_cross_referencing.markdown b/doc/tutorials/introduction/cross_referencing/tutorial_cross_referencing.markdown
index e2948beee9a1d0dde3b80f13dcc51bf0c4709052..4908771aec0d4249793d9593dcc04fcf51e55c44 100644
--- a/doc/tutorials/introduction/cross_referencing/tutorial_cross_referencing.markdown
+++ b/doc/tutorials/introduction/cross_referencing/tutorial_cross_referencing.markdown
@@ -46,14 +46,14 @@ Open your Doxyfile using your favorite text editor and search for the key
 `TAGFILES`. Change it as follows:
 
 @code
-TAGFILES = ./docs/doxygen-tags/opencv.tag=http://docs.opencv.org/4.5.1
+TAGFILES = ./docs/doxygen-tags/opencv.tag=http://docs.opencv.org/4.5.2
 @endcode
 
 If you had other definitions already, you can append the line using a `\`:
 
 @code
 TAGFILES = ./docs/doxygen-tags/libstdc++.tag=https://gcc.gnu.org/onlinedocs/libstdc++/latest-doxygen \
-           ./docs/doxygen-tags/opencv.tag=http://docs.opencv.org/4.5.1
+           ./docs/doxygen-tags/opencv.tag=http://docs.opencv.org/4.5.2
 @endcode
 
 Doxygen can now use the information from the tag file to link to the OpenCV
diff --git a/modules/core/include/opencv2/core/version.hpp b/modules/core/include/opencv2/core/version.hpp
index ce030a220480864928536bcaa326b2d6dbd9206e..fd3c835994e52296d321e399cbff2cd7eb302c09 100644
--- a/modules/core/include/opencv2/core/version.hpp
+++ b/modules/core/include/opencv2/core/version.hpp
@@ -7,8 +7,8 @@
 
 #define CV_VERSION_MAJOR    4
 #define CV_VERSION_MINOR    5
-#define CV_VERSION_REVISION 1
-#define CV_VERSION_STATUS   "-dev"
+#define CV_VERSION_REVISION 2
+#define CV_VERSION_STATUS   "-pre"
 
 #define CVAUX_STR_EXP(__A)  #__A
 #define CVAUX_STR(__A)      CVAUX_STR_EXP(__A)
diff --git a/modules/dnn/include/opencv2/dnn/version.hpp b/modules/dnn/include/opencv2/dnn/version.hpp
index 5ba9ac60c3f9ef119d3a4b2b1857da1dba5e7099..43191b89837a87d6217e0baf7847e0f020ad7806 100644
--- a/modules/dnn/include/opencv2/dnn/version.hpp
+++ b/modules/dnn/include/opencv2/dnn/version.hpp
@@ -6,7 +6,7 @@
 #define OPENCV_DNN_VERSION_HPP
 
 /// Use with major OpenCV version only.
-#define OPENCV_DNN_API_VERSION 20210205
+#define OPENCV_DNN_API_VERSION 20210301
 
 #if !defined CV_DOXYGEN && !defined CV_STATIC_ANALYSIS && !defined CV_DNN_DONT_ADD_INLINE_NS
 #define CV__DNN_INLINE_NS __CV_CAT(dnn4_v, OPENCV_DNN_API_VERSION)
diff --git a/modules/python/package/setup.py b/modules/python/package/setup.py
index f7379b356a89fe71720ab4c69c58e4366aa15b6b..ddb8ca70b09268b6a5f4843c9b43bf5f4f538d46 100644
--- a/modules/python/package/setup.py
+++ b/modules/python/package/setup.py
@@ -9,7 +9,7 @@ def main():
     os.chdir(SCRIPT_DIR)
 
     package_name = 'opencv'
-    package_version = os.environ.get('OPENCV_VERSION', '4.5.1')  # TODO
+    package_version = os.environ.get('OPENCV_VERSION', '4.5.2')  # TODO
 
     long_description = 'Open Source Computer Vision Library Python bindings'  # TODO
 
diff --git a/platforms/maven/opencv-it/pom.xml b/platforms/maven/opencv-it/pom.xml
index 1849259c36d103033a0da185f630b5221a5a02d6..efb234fa03938facc3bbc63ab2e18445c580ec57 100644
--- a/platforms/maven/opencv-it/pom.xml
+++ b/platforms/maven/opencv-it/pom.xml
@@ -4,7 +4,7 @@
     <parent>
         <groupId>org.opencv</groupId>
         <artifactId>opencv-parent</artifactId>
-        <version>4.5.1</version>
+        <version>4.5.2</version>
     </parent>
     <groupId>org.opencv</groupId>
     <artifactId>opencv-it</artifactId>
diff --git a/platforms/maven/opencv/pom.xml b/platforms/maven/opencv/pom.xml
index d6c630dddb14a926a4f401cc85dbb8ea53cd784e..ca95f4b74d6fcb7dffa899edd04c29c3cec737d4 100644
--- a/platforms/maven/opencv/pom.xml
+++ b/platforms/maven/opencv/pom.xml
@@ -4,7 +4,7 @@
     <parent>
         <groupId>org.opencv</groupId>
         <artifactId>opencv-parent</artifactId>
-        <version>4.5.1</version>
+        <version>4.5.2</version>
     </parent>
     <groupId>org.opencv</groupId>
     <artifactId>opencv</artifactId>
diff --git a/platforms/maven/pom.xml b/platforms/maven/pom.xml
index 934634536ab963d3ca9b0046460b3117c3ce44e2..42de60ab09ee8637aeb4e783f1f85b875da326cc 100644
--- a/platforms/maven/pom.xml
+++ b/platforms/maven/pom.xml
@@ -3,7 +3,7 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>org.opencv</groupId>
     <artifactId>opencv-parent</artifactId>
-    <version>4.5.1</version>
+    <version>4.5.2</version>
     <packaging>pom</packaging>
     <name>OpenCV Parent POM</name>
     <licenses>